double log2(double x) /* wrapper log10 */ { #ifdef _IEEE_LIBM return __ieee754_log2(x); #else double z; z = __ieee754_log2(x); if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; if(x<=0.0) { if(x==0.0) return __kernel_standard(x,x,48); /* log2(0) */ else return __kernel_standard(x,x,49); /* log2(x<0) */ } else return z; #endif }
/* wrapper log2(x) */ double __log2 (double x) { if (__builtin_expect (islessequal (x, 0.0), 0) && _LIB_VERSION != _IEEE_) { if (x == 0.0) { feraiseexcept (FE_DIVBYZERO); return __kernel_standard (x, x, 48); /* log2(0) */ } else { feraiseexcept (FE_INVALID); return __kernel_standard (x, x, 49); /* log2(x<0) */ } } return __ieee754_log2 (x); }
/* wrapper log2f(x) */ float log2f (float x) { #if defined(__UCLIBC_HAS_FENV__) if (__builtin_expect (islessequal (x, 0.0f), 0) && _LIB_VERSION != _IEEE_) { if (x == 0.0) { feraiseexcept (FE_DIVBYZERO); return __kernel_standard_f (x, x, 148); /* log2(0) */ } else { feraiseexcept (FE_INVALID); return __kernel_standard_f (x, x, 149); /* log2(x<0) */ } } #endif return (float) __ieee754_log2 ((double) x); }